Systems and methods for supporting an enhanced serving cell change when moving among different cell types

ABSTRACT

A system and method enable handover from a DC-HSUPA-capable node in a cellular wireless network to a non-DC-HSUPA-capable node. According to various aspects of the present disclosure, a handover may implement a legacy serving cell change procedure or an enhanced serving cell change procedure. In either case, signaling from the network to user equipment includes information to enable the user equipment to change or remove an Active Set when undergoing a handover from a cell with two uplink carriers and accordingly two Active Sets, to a cell with one uplink carrier and accordingly one Active Set.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. Pat. No. 8,942,209, titled“SYSTEMS AND METHODS FOR SUPPORTING AN ENHANCED SERVING CELL CHANGE WHENMOVING AMONG DIFFERENT CELL TYPES,” filed on Aug. 11, 2010 and issued onJan. 27, 2015, which claims the benefit of U.S. Provisional PatentApplication No. 61/233,421, titled “SUPPORT FOR E-SCC WHEN UE GOES FROMDC-HSUPA CAPABLE CELL TO NON-DC-HSUPA CAPABLE CELL,” filed on Aug. 12,2009, the disclosures of which are expressly incorporated by referenceherein in their entirety.

BACKGROUND

Field

Aspects of the present disclosure relate generally to wirelesscommunication systems, and more particularly, to handovers betweendifferent cell types in a cellular wireless communication system.

Background

Wireless communication networks are widely deployed to provide variouscommunication services such as telephony, video, data, messaging,broadcasts, and so on. Such networks, which are usually multiple accessnetworks, support communications for multiple users by sharing theavailable network resources. One example of such a network is the UMTSTerrestrial Radio Access Network (UTRAN). The UTRAN is the radio accessnetwork (RAN) defined as a part of the Universal MobileTelecommunications System (UMTS), a third generation (3G) mobile phonetechnology supported by the 3rd Generation Partnership Project (3GPP).The UMTS, which is the successor to Global System for MobileCommunications (GSM) technologies, currently supports various airinterface standards, such as Wideband-Code Division Multiple Access(W-CDMA), Time Division-Code Division Multiple Access (TD-CDMA), andTime Division-Synchronous Code Division Multiple Access (TD-SCDMA). TheUMTS also supports enhanced 3G data communications protocols, such asHigh Speed Packet Access (HSDPA), which provides higher data transferspeeds and capacity to associated UMTS networks.

As the demand for mobile broadband access continues to increase,research and development continue to advance the UMTS technologies notonly to meet the growing demand for mobile broadband access, but toadvance and enhance the user experience with mobile communications.

SUMMARY

A system and method enable handover from a DC-HSUPA-capable node in acellular wireless network to a non-DC-HSUPA-capable node. According tovarious aspects of the present disclosure, a handover may implement alegacy serving cell change procedure or an enhanced serving cell changeprocedure. In either case, signaling from the network to user equipmentmay include information to enable the user equipment to change or removean Active Set when undergoing a handover from a cell with two uplinkcarriers and accordingly two Active Sets, to a cell with one uplinkcarrier and accordingly one Active Set.

In an exemplary aspect of the disclosure, a method of communication in awireless network includes establishing communication with the wirelessnetwork utilizing a first carrier and a second carrier for each of anuplink and a downlink, maintaining a first active set comprising a listof any cells in the wireless network that meet first criteria, the firstactive set corresponding to the first carrier, maintaining a secondactive set comprising a list of any cells in the wireless network thatmeet second criteria, the second active set corresponding to the secondcarrier, and receiving a notification not to utilize the second activeset or the second carrier after a handover to a target cell.

In another exemplary aspect of the disclosure, an apparatus forcommunication in a wireless network includes means for establishingcommunication with the wireless network utilizing a first carrier and asecond carrier for each of an uplink and a downlink, means formaintaining a first active set comprising a list of any cells in thewireless network that meet first criteria, the first active setcorresponding to the first carrier, means for maintaining a secondactive set comprising a list of any cells in the wireless network thatmeet second criteria, the second active set corresponding to the secondcarrier, and means for receiving a notification not to utilize thesecond active set or the second carrier after a handover to a targetcell.

In yet another exemplary aspect of the disclosure, a computer programproduct for use in a wireless network includes a computer-readablemedium comprising code for establishing communication with the wirelessnetwork utilizing a first carrier and a second carrier for each of anuplink and a downlink, maintaining a first active set comprising a listof any cells in the wireless network that meet first criteria, the firstactive set corresponding to the first carrier, maintaining a secondactive set comprising a list of any cells in the wireless network thatmeet second criteria, the second active set corresponding to the secondcarrier, and receiving a notification not to utilize the second activeset or the second carrier after a handover to a target cell.

In yet another exemplary aspect of the disclosure, an apparatus forcommunication in a wireless network includes at least one processor anda memory coupled to the at least one processor. Here, the at least oneprocessor is configured to establish communication with the wirelessnetwork utilizing a first carrier and a second carrier for each of anuplink and a downlink, maintain a first active set comprising a list ofany cells in the wireless network that meet first criteria, the firstactive set corresponding to the first carrier, maintain a second activeset comprising a list of any cells in the wireless network that meetsecond criteria, the second active set corresponding to the secondcarrier, and receive a notification not to utilize the second active setor the second carrier after a handover to a target cell.

These and other aspects of the invention will become more fullyunderstood upon a review of the detailed description, which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a hardware implementationfor an apparatus employing a processing system.

FIG. 2 is a block diagram conceptually illustrating an example of atelecommunications system.

FIG. 3 is a conceptual diagram illustrating an example of an accessnetwork.

FIG. 4 is a block diagram conceptually illustrating an example of a NodeB in communication with a UE in a telecommunications system.

FIG. 5 is a conceptual diagram illustrating a soft handover in a singlecarrier HSDPA system.

FIG. 6 is a conceptual diagram illustrating a soft handover in a dualcarrier DC-HSDPA system.

FIG. 7 is a call flow diagram illustrating a legacy serving cell changeprocedure.

FIG. 8 is a call flow diagram illustrating an enhanced serving cellchange procedure.

FIG. 9 is a flow chart illustrating a procedure for a handover from aDC-HSUPA system to a non-DC-HSUPA-capable system.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented withreference to various apparatus and methods. These apparatus and methodswill be described in the following detailed description and illustratedin the accompanying drawing by various blocks, modules, components,circuits, steps, processes, algorithms, etc. (collectively referred toas “elements”). These elements may be implemented using electronichardware, computer software, or any combination thereof. Whether suchelements are implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem.

FIG. 1 is a conceptual diagram illustrating an example of a hardwareimplementation for an apparatus 100 employing a processing system 114.In this example, the processing system 114 may be implemented with a busarchitecture, represented generally by the bus 102. The bus 102 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 114 and the overall designconstraints. The bus 102 links together various circuits including oneor more processors, represented generally by the processor 104, andcomputer-readable media, represented generally by the computer-readablemedium 106. The bus 102 may also link various other circuits such astiming sources, peripherals, voltage regulators, and power managementcircuits, which are well known in the art, and therefore, will not bedescribed any further. A bus interface 108 provides an interface betweenthe bus 102 and a transceiver 110. The transceiver 110 provides a meansfor communicating with various other apparatus over a transmissionmedium. Depending upon the nature of the apparatus, a user interface 112(e.g., keypad, display, speaker, microphone, joystick) may also beprovided.

The processor 104 is responsible for managing the bus 102 and generalprocessing, including the execution of software stored on thecomputer-readable medium 106. The software, when executed by theprocessor 104, causes the processing system 114 to perform the variousfunctions described infra for any particular apparatus. Thecomputer-readable medium 106 may also be used for storing data that ismanipulated by the processor 104 when executing software.

The various concepts presented throughout this disclosure may beimplemented across a broad variety of telecommunication systems, networkarchitectures, and communication standards. By way of example andwithout limitation, the aspects of the present disclosure illustrated inFIG. 2 are presented with reference to a UMTS system 200 employing aW-CDMA air interface. A UMTS network includes three interacting domains:a Core Network (CN) 204, a UMTS Terrestrial Radio Access Network (UTRAN)202, and User Equipment (UE) 210. In this example, the UTRAN 202provides various wireless services including telephony, video, data,messaging, broadcasts, and/or other services. The UTRAN 202 may includea plurality of Radio Network Subsystems (RNSs) such as RNS 207, eachincluding a respective Radio Network Controller (RNC) such as an RNC206. Here, the UTRAN 202 may include any number of RNCs 206 and RNSs 207in addition to the RNCs 206 and RNSs 207 illustrated herein. The RNC 206is an apparatus responsible for, among other things, assigning,reconfiguring and releasing radio resources within the RNS 207. The RNC206 may be interconnected to other RNCs (not shown) in the UTRAN 202through various types of interfaces such as a direct physicalconnection, a virtual network, or the like, using any suitable transportnetwork.

Communication between a UE 210 and a Node B 208 may be considered asincluding a physical (PHY) layer and a medium access control (MAC)layer. Further, communication between a UE 210 and an RNC 206 by way ofa respective Node B 208 may be considered as including a radio resourcecontrol (RRC) layer. In the instant specification, the PHY layer may beconsidered layer 1; the MAC layer may be considered layer 2; and the RRClayer may be considered layer 3. Information hereinbelow utilizesterminology introduced in Radio Resource Control (RRC) ProtocolSpecification, 3GPP TS 25.331 v9.1.0, incorporated herein by reference.

The geographic region covered by the RNS 207 may be divided into anumber of cells, with a radio transceiver apparatus serving each cell. Aradio transceiver apparatus is commonly referred to as a Node B in UMTSapplications, but may also be referred to by those skilled in the art asa base station (BS), a base transceiver station (BTS), a radio basestation, a radio transceiver, a transceiver function, a basic serviceset (BSS), an extended service set (ESS), an access point (AP), or someother suitable terminology. Moreover, certain applications may utilizefemtocells served by a home Node B (HNB), home enhanced Node B (HeNB),femto access point (FAP), access point base station, etc. For clarity,in the illustrated example, three Node Bs 208 are shown in each RNS 207;however, the RNSs 207 may include any number of wireless Node Bs. TheNode Bs 208 provide wireless access points to a core network (CN) 204for any number of mobile apparatuses. Examples of a mobile apparatusinclude a cellular phone, a smart phone, a session initiation protocol(SIP) phone, a laptop, a notebook, a netbook, a smartbook, a personaldigital assistant (PDA), a satellite radio, a global positioning system(GPS) device, a multimedia device, a video device, a digital audioplayer (e.g., MP3 player), a camera, a game console, or any othersimilar functioning device. The mobile apparatus is commonly referred toas UE in UMTS applications, but may also be referred to by those skilledin the art as a mobile station (MS), a subscriber station, a mobileunit, a subscriber unit, a wireless unit, a remote unit, a mobiledevice, a wireless device, a wireless communications device, a remotedevice, a mobile subscriber station, an access terminal (AT), a mobileterminal, a wireless terminal, a remote terminal, a handset, a terminal,a user agent, a mobile client, a client, or some other suitableterminology. In a UMTS system, the UE 210 may further include auniversal subscriber identity module (USIM) 211, which contains a user'ssubscription information to a network. For illustrative purposes, one UE210 is shown in communication with a number of the Node Bs 208. Thedownlink (DL), also called the forward link, refers to the communicationlink from a Node B 208 to a UE 210, and the uplink (UL), also called thereverse link, refers to the communication link from a UE 210 to a Node B208.

The CN domain 204 interfaces with one or more access networks, such asthe UTRAN 202. As shown, the core network 204 is a GSM core network.However, as those skilled in the art will recognize, the variousconcepts presented throughout this disclosure may be implemented in aRAN, or other suitable access network, to provide UEs with access totypes of core networks other than GSM networks.

The core network 204 includes a circuit-switched (CS) domain and apacket-switched (PS) domain. Some of the circuit-switched elements are aMobile services Switching Centre (MSC), a Visitor location register(VLR) and a Gateway MSC. Packet-switched elements include a Serving GPRSSupport Node (SGSN) and a Gateway GPRS Support Node (GGSN). Some networkelements, like EIR, HLR, VLR and AuC may be shared by both of thecircuit-switched and packet-switched domains. In the illustratedexample, the core network 204 supports circuit-switched services with aMSC 212 and a GMSC 214. In some applications, the GMSC 214 may bereferred to as a media gateway (MGW). One or more RNCs, such as the RNC206, may be connected to the MSC 212. The MSC 212 is an apparatus thatcontrols call setup, call routing, and UE mobility functions. The MSC212 also includes a visitor location register (VLR) that containssubscriber-related information for the duration that a UE is in thecoverage area of the MSC 212. The GMSC 214 provides a gateway throughthe MSC 212 for the UE to access a circuit-switched network 216. TheGMSC 214 includes a home location register (HLR) 215 containingsubscriber data, such as the data reflecting the details of the servicesto which a particular user has subscribed. The HLR is also associatedwith an authentication center (AuC) that contains subscriber-specificauthentication data. When a call is received for a particular UE, theGMSC 214 queries the HLR 215 to determine the UE's location and forwardsthe call to the particular MSC serving that location.

The core network 204 also supports packet-data services with a servingGPRS support node (SGSN) 218 and a gateway GPRS support node (GGSN) 220.GPRS, which stands for General Packet Radio Service, is designed toprovide packet-data services at speeds higher than those available withstandard circuit-switched data services. The GGSN 220 provides aconnection for the UTRAN 202 to a packet-based network 222. Thepacket-based network 222 may be the Internet, a private data network, orsome other suitable packet-based network. The primary function of theGGSN 220 is to provide the UEs 210 with packet-based networkconnectivity. Data packets may be transferred between the GGSN 220 andthe UEs 210 through the SGSN 218, which performs primarily the samefunctions in the packet-based domain as the MSC 212 performs in thecircuit-switched domain.

The UMTS air interface is a spread spectrum Direct-Sequence CodeDivision Multiple Access (DS-CDMA) system. The spread spectrum DS-CDMAspreads user data through multiplication by a sequence of pseudorandombits called chips. The W-CDMA air interface for UMTS is based on suchdirect sequence spread spectrum technology and additionally calls for afrequency division duplexing (FDD). FDD uses a different carrierfrequency for the uplink (UL) and downlink (DL) between a Node B 208 anda UE 210. Another air interface for UMTS that utilizes DS-CDMA, and usestime division duplexing, is the TD-SCDMA air interface. Those skilled inthe art will recognize that although various examples described hereinmay refer to a WCDMA air interface, the underlying principles areequally applicable to a TD-SCDMA air interface.

Referring to FIG. 3, an access network 300 in a UTRAN architecture isillustrated. The multiple access wireless communication system includesmultiple cellular regions, including geographic coverage areas 302, 304,and 306, each of which may include one or more sectors. The multiplesectors can be formed by groups of antennas with each antennaresponsible for communication with UEs in a portion of the coveragearea. For example, in coverage area 302, antenna groups 312, 314, and316 may each correspond to a different sector. In coverage area 304,antenna groups 318, 320, and 322 each correspond to a different sector.In coverage area 306, antenna groups 324, 326, and 328 each correspondto a different sector. The coverage areas 302, 304 and 306 may includeseveral wireless communication devices, e.g., User Equipment or UEs,which may be in communication with one or more sectors of each coveragearea 302, 304 or 306. For example, UEs 330 and 332 may be incommunication with Node B 342, UEs 334 and 336 may be in communicationwith Node B 344, and UEs 338 and 340 can be in communication with Node B346. Here, each Node B 342, 344, 346 is configured to provide an accesspoint to a core network 204 (see FIG. 2) for all the UEs 330, 332, 334,336, 338, 340 in the respective coverage areas 302, 304, and 306.

As the UE 334 moves from the illustrated location in coverage area 304into coverage area 306, a serving cell change (SCC) or handover mayoccur in which communication with the UE 334 transitions from thecoverage area 304, which may be served by a Node B referred to as thesource cell, to coverage area 306, which may be served by a Node Breferred to as the target cell. Management of the handover procedure maytake place at the UE 334, at the Node Bs corresponding to the respectivecoverage areas, at a radio network controller 206 (see FIG. 2), or atanother suitable node in the wireless network. For example, during acall with the source cell 304, or at any other time, the UE 334 maymonitor various parameters of the source cell 304 as well as variousparameters of neighboring cells such as those served by Node Bscorresponding to coverage areas 306 and 302. Further, depending on thequality of these parameters, the UE 334 may maintain communication withone or more of the neighboring cells. During this time, the UE 334 maymaintain an Active Set, that is, a list of neighboring cells that the UE334 is simultaneously connected to (i.e., the UTRA Node Bs that arecurrently assigning a downlink dedicated physical channel DPCH orfractional downlink dedicated physical channel F-DPCH to the UE 334 mayconstitute the Active Set).

The modulation and multiple access scheme employed by the access network300 may vary depending on the particular telecommunications standardbeing deployed. By way of example, the standard may includeEvolution-Data Optimized (EV-DO) or Ultra Mobile Broadband (UMB). EV-DOand UMB are air interface standards promulgated by the 3rd GenerationPartnership Project 2 (3GPP2) as part of the CDMA2000 family ofstandards and employs CDMA to provide broadband Internet access tomobile stations. The standard may alternately be Universal TerrestrialRadio Access (UTRA) employing Wideband-CDMA (W-CDMA) and other variantsof CDMA, such as TD-SCDMA; Global System for Mobile Communications (GSM)employing TDMA; and Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB),IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDMemploying OFDMA. UTRA, E-UTRA, UMTS, LTE, LTE Advanced, and GSM aredescribed in documents from the 3GPP organization. CDMA2000 and UMB aredescribed in documents from the 3GPP2 organization. The actual wirelesscommunication standard and the multiple access technology employed willdepend on the specific application and the overall design constraintsimposed on the system.

FIG. 4 is a block diagram of a Node B 410 in communication with a UE450, where the Node B 410 may be the Node B 208 in FIG. 2, and the UE450 may be the UE 210 in FIG. 2. In the downlink communication, atransmit processor 420 may receive data from a data source 412 andcontrol signals from a controller/processor 440. The transmit processor420 provides various signal processing functions for the data andcontrol signals, as well as reference signals (e.g., pilot signals). Forexample, the transmit processor 420 may provide cyclic redundancy check(CRC) codes for error detection, coding and interleaving to facilitateforward error correction (FEC), mapping to signal constellations basedon various modulation schemes (e.g., binary phase-shift keying (BPSK),quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK),M-quadrature amplitude modulation (M-QAM), and the like), spreading withorthogonal variable spreading factors (OVSF), and multiplying withscrambling codes to produce a series of symbols. Channel estimates froma channel processor 444 may be used by a controller/processor 440 todetermine the coding, modulation, spreading, and/or scrambling schemesfor the transmit processor 420. These channel estimates may be derivedfrom a reference signal transmitted by the UE 450 or from feedback fromthe UE 450. The symbols generated by the transmit processor 420 areprovided to a transmit frame processor 430 to create a frame structure.The transmit frame processor 430 creates this frame structure bymultiplexing the symbols with information from the controller/processor440, resulting in a series of frames. The frames are then provided to atransmitter 432, which provides various signal conditioning functionsincluding amplifying, filtering, and modulating the frames onto acarrier for downlink transmission over the wireless medium throughantenna 434. The antenna 434 may include one or more antennas, forexample, including beam steering bidirectional adaptive antenna arraysor other similar beam technologies.

At the UE 450, a receiver 454 receives the downlink transmission throughan antenna 452 and processes the transmission to recover the informationmodulated onto the carrier. The information recovered by the receiver454 is provided to a receive frame processor 460, which parses eachframe, and provides information from the frames to a channel processor494 and the data, control, and reference signals to a receive processor470. The receive processor 470 then performs the inverse of theprocessing performed by the transmit processor 420 in the Node B 410.More specifically, the receive processor 470 descrambles and despreadsthe symbols, and then determines the most likely signal constellationpoints transmitted by the Node B 410 based on the modulation scheme.These soft decisions may be based on channel estimates computed by thechannel processor 494. The soft decisions are then decoded anddeinterleaved to recover the data, control, and reference signals. TheCRC codes are then checked to determine whether the frames weresuccessfully decoded. The data carried by the successfully decodedframes will then be provided to a data sink 472, which representsapplications running in the UE 450 and/or various user interfaces (e.g.,display). Control signals carried by successfully decoded frames will beprovided to a controller/processor 490. When frames are unsuccessfullydecoded by the receiver processor 470, the controller/processor 490 mayalso use an acknowledgement (ACK) and/or negative acknowledgement (NACK)protocol to support retransmission requests for those frames.

In the uplink, data from a data source 478 and control signals from thecontroller/processor 490 are provided to a transmit processor 480. Thedata source 478 may represent applications running in the UE 450 andvarious user interfaces (e.g., keyboard). Similar to the functionalitydescribed in connection with the downlink transmission by the Node B410, the transmit processor 480 provides various signal processingfunctions including CRC codes, coding and interleaving to facilitateFEC, mapping to signal constellations, spreading with OVSFs, andscrambling to produce a series of symbols. Channel estimates, derived bythe channel processor 494 from a reference signal transmitted by theNode B 410 or from feedback contained in the midamble transmitted by theNode B 410, may be used to select the appropriate coding, modulation,spreading, and/or scrambling schemes. The symbols produced by thetransmit processor 480 will be provided to a transmit frame processor482 to create a frame structure. The transmit frame processor 482creates this frame structure by multiplexing the symbols withinformation from the controller/processor 490, resulting in a series offrames. The frames are then provided to a transmitter 456, whichprovides various signal conditioning functions including amplification,filtering, and modulating the frames onto a carrier for uplinktransmission over the wireless medium through the antenna 452.

The uplink transmission is processed at the Node B 410 in a mannersimilar to that described in connection with the receiver function atthe UE 450. A receiver 435 receives the uplink transmission through theantenna 434 and processes the transmission to recover the informationmodulated onto the carrier. The information recovered by the receiver435 is provided to a receive frame processor 436, which parses eachframe, and provides information from the frames to the channel processor444 and the data, control, and reference signals to a receive processor438. The receive processor 438 performs the inverse of the processingperformed by the transmit processor 480 in the UE 450. The data andcontrol signals carried by the successfully decoded frames may then beprovided to a data sink 439 and the controller/processor, respectively.If some of the frames were unsuccessfully decoded by the receiveprocessor, the controller/processor 440 may also use an ACK and/or NACKprotocol to support retransmission requests for those frames.

The controller/processors 440 and 490 may be used to direct theoperation at the Node B 410 and the UE 450, respectively. For example,the controller/processors 440 and 490 may provide various functionsincluding timing, peripheral interfaces, voltage regulation, powermanagement, and other control functions. The computer readable media ofmemories 442 and 492 may store data and software for the Node B 410 andthe UE 450, respectively. A scheduler/processor 446 at the Node B 410may be used to allocate resources to the UEs and schedule downlinkand/or uplink transmissions for the UEs.

Various cellular wireless communication systems may utilize amake-before-break serving cell change (SCC) frequently referred to as asoft handover. During a soft handover, a UE establishes communicationwith the target cell before breaking the connection with the sourcecell. FIG. 5 illustrates a UE 502 engaged in a soft handover between asource cell 504 and a target cell 506 in a single carrier system (i.e.,using only carrier frequency f1). In the illustration, the source cell504 is the serving cell, meaning that the source cell 504 is providing adownlink to the UE, including a high-speed data channel 514. Further,both the source cell 504 and the target 506 cell provide transmit powercontrol (TPC) information 508, 510 to the UE 502 on suitable channels.The uplink 512 from the UE 502 is decoded by both the source cell 504and the target cell 506. Here, while the UE 502 is in soft handover, theHSDPA channel 514 is only provided by the serving cell 504.

In release-8 of the 3GPP family of standards, among other improvements,the downlink for HSDPA communication was specified to enable dualcarriers (DC-HSDPA). FIG. 6 illustrates a UE 602 engaged in a softhandover between a source cell 604 and a target cell 606 in a DC-HSDPAsystem. As in FIG. 5, the UE 602 is transmitting an uplink 612 that isbeing decoded by the source cell 604 and the target cell 606, and thesource and target cells each provide TPC information 608, 610 to the UE602 on suitable downlink channels. Also, the source cell or serving cell604 provides one of its downlinks on a high-speed data channel 614. Eachof these signals, that is, the uplink 612, the downlink TPC information608, 610, and the downlink data 614, share a first carrier frequency f1,separated by a suitable duplex distance for the respective uplink anddownlink transmissions (assuming a frequency division duplex system). Inaddition, the serving cell 604 provides a second downlink stream 616 ona second carrier frequency f2. Hereinafter, the terminologies “anchorcarrier” and “primary carrier”, and “supplementary carrier” and“secondary carrier” will be used interchangeably, respectively. The“first carrier” (or “second carrier”) may be either the anchor carrieror the secondary carrier. For multi-carrier operation more than onesupplementary carrier or secondary carrier may exist. Frequently, thefirst carrier f1, which is shared by the uplink and downlink, is calledthe anchor carrier, while the second carrier f2, which provides adownlink 616 from the serving cell 604, is referred to as the secondarycarrier. Because there is no uplink channel on the second carrier f2,the UE 602 generally does not maintain an Active Set for the secondcarrier, and only maintains an Active Set for the first carrier. Here,as in the previous example, while the UE 602 is in soft handover, alldownlink data (here, on two HSDPA carriers) is provided exclusively bythe serving cell 604.

FIG. 7 is a call flow diagram illustrating a soft handover process thatmay be utilized in a single carrier system and in a dual carrier system,referred to herein as a “legacy” serving cell change (SCC). Thoseskilled in the art will comprehend that the illustration does not showall signaling between the respective nodes, but only shows certainmessages sent between the respective nodes for ease of illustration.

As discussed above, a UE 702 may monitor certain parameters andcharacteristics of the serving cell 704 and one or more neighboringcells. As an example for an FDD system, the UE 702 may monitor a pilotsignal power of the respective cells. When one of the neighboring cells,i.e., cell 2 706, has a pilot signal power that exceeds a threshold orreaches a certain reporting range, (e.g., reaching within approximatelyX dB of the pilot signal strength of the serving cell 704), the UE 702may provide an RRC message 710 (i.e., a layer 3 message) frequentlycalled a Measurement Report message including notification of “event1a.” The RNC 708 may then respond to the Measurement Report message 710with an RRC Active Set Update message 712, instructing the UE 702 to addcell 2 706 to its Active Set.

Later, if and when the UE 702 detects that the pilot signal power ofcell 2 706 exceeds that of cell 1 704, the UE 702 may provide a secondRRC Measurement Report message 714 including notification of “event 1d.”The RNC 708 may then respond to the Measurement Report message 714 withan RRC Transport Channel Reconfiguration Request message (or othersimilar message) 716 including configuration information for setting upa connection with cell 2 706, also referred to as the target cell. Afterthe handover is complete, cell 2 706 is referred to as the serving cell.It should be noted that each of the above signals provided from the RNC708 to the UE 702 (i.e., the Active Set Update message 712 and theTransport Channel Reconfiguration Request message 716) are providedutilizing the downlink from the source cell, i.e., cell 1 704.

In some cases, such as when a UE is moving rapidly from one cell toanother, the signal quality from the serving cell may degrade toorapidly, and processing and/or transmission delays may result in adropped call. That is, utilizing the legacy SCC procedure discussedabove and illustrated in FIG. 7, if the signal quality from cell 1 704degrades too rapidly, the UE 702 may not receive the RRC TransportChannel Reconfiguration Request message 716 on the downlink from cell 1704. Here, because this message included synchronization and otherinformation related to setting up communication with cell 2 706, the UE702 lacks this information and is unable to establish a connection withcell 2 706 before the connection with cell 1 704 is lost, resulting in adropped call.

Thus, another enhancement provided in release-8 was the enhanced servingcell change (E-SCC). Briefly, E-SCC is an improved soft handoverprocedure that reduces dropped calls during a situation where a UE ismoving rapidly from one cell to another. FIG. 8 is a call flow diagramillustrating a soft handover process in an FDD HSDPA or a DC-HSDPAsystem as illustrated in either one of FIG. 5 or 6. As in the scenarioillustrated in FIG. 7, here, when a neighboring cell, i.e., cell 2 806,has a pilot signal power that exceeds a threshold, the UE 802 mayprovide an RRC Measurement Report message 810 including notification ofevent 1a. The RNC 808 may then respond to the Measurement Report message810 with an RRC Active Set Update message 812. However, here, the RRCActive Set Update message 812 includes pre-configuration informationrelating to cell 2 806, which the UE 802 may then store for utilizationif cell 2 806 later becomes the serving cell for that UE 802. Now, ifand when the pilot signal power of cell 2 806 exceeds that of cell 1804, the UE 802 may provide a second RRC Measurement Report message 814including notification of event 1d. In response to the MeasurementReport message 814, the RNC 808 may then instruct cell 2 806 to transmita physical (PHY) layer indication 816, which in one example may simplybe a single bit of information, to instruct the UE 802 to change itsserving cell to the target cell, that is, cell 2 806. Because the RRCActive Set Update message 812 already received by the UE 802 includedthe needed information relating to cell 2 806, the UE 802 does notrequire any further transmissions (such as RRC messages) from cell 1 804to complete the handover. This is basically how E-SCC improves ahandover in a scenario where the signal from cell 1 804 drops off veryquickly.

Moving on, in release-9 of the 3GPP family of standards, dual carrierswere provided for both the high-speed downlink, as before, as well asthe high-speed uplink (DC-HSUPA). Prior to release-9, during a softhandover in DC-HSDPA, as illustrated in FIG. 6, while the first carrierf1 utilized the same scheme in uplink and downlink as that of the singlecarrier soft handover in FIG. 5, the second carrier f2 only provided adownlink channel 616 from the serving cell 604. However, in arelease-9-capable DC-HSUPA system, the second carrier f2 utilizes thesame scheme in uplink and downlink as that of the first carrier f1,including TPC information on downlink channels from the source cell andthe target cell, and an uplink channel separated from the seconddownlink by the duplex distance. Thus, in a DC-HSUPA system, an ActiveSet is maintained in the UE for each of the first carrier f1 and thesecond carrier f2.

As networks are upgraded from release-8 systems to release-9 systems, itis practically inevitable that some Node Bs in a service area will beupgraded to release-9 while other Node Bs in the same service area willremain as release-8 units. Thus, when a UE is utilizing such a network,a handover from a release-9 Node B to a release-8 Node B, andvice-versa, is bound to occur. An issue with this scenario relates tothe situation wherein a UE, served by a source cell configured to accepttwo high-speed uplink carriers from the UE, maintains two Active Sets,one corresponding to neighboring cells utilizing each respective carrierfrequency. When the UE undergoes a serving cell change to the release-8cell, which is limited to supporting one uplink carrier frequency duringa communication session with the UE, the UE may not require both of theActive Sets. That is, when a release-8 cell is the serving cell, the UEonly maintains one Active Set corresponding to the anchor or primarycarrier frequency, and does not maintain an Active Set corresponding tothe secondary downlink carrier. Here, an issue that arises is related toenhanced serving cell change (E-SCC). That is, when E-SCC was defined inthe release-8 specifications, DC-HSUPA had not yet been introduced, sothe maintenance of more than one Active Set was not contemplated. Thus,the signaling related to removing the Active Set corresponding to thesecondary carrier was not previously defined.

According to an aspect of the present disclosure, in the case of alegacy SCC, as illustrated in FIG. 7, the RRC Transport ChannelReconfiguration Request message may further include informationindicating that cell 2 is not a release-9-capable cell, and/orinformation to enable the UE to remove the active set corresponding toone of the two carriers.

According to another aspect of the present disclosure, in the case of anE-SCC, as illustrated in FIG. 8, the RRC Active Set Update message thatincludes pre-configuration information corresponding to cell 2 mayfurther include information indicating that cell 2 is not a release-9capable cell, and/or information to enable the UE to remove the activeset corresponding to one of the two carriers.

FIG. 9 is a flow chart illustrating exemplary processes of performing ahandover from a release-9-capable DC-HSUPA cell to a release-8 DC-HSDPAcell according to certain aspects of the disclosure. In the figure,blocks to the left represent a course of action when utilizing a legacySCC, and blocks to the right represent a course of action when utilizingE-SCC. In some aspects of the disclosure, the process illustrated inFIG. 9 may be performed by a processing system 100 such as thatillustrated in FIG. 1. In some aspects of the disclosure, the processillustrated in FIG. 9 may be performed by a UE 210 in communication witha plurality of Node Bs 208 and at least one RNC 206 in a wirelessnetwork 200 such as that illustrated in FIG. 2. In some aspects of thedisclosure, various steps of the process illustrated in FIG. 9 may beperformed by combinations of the receiver 454, transmitter 456, theprocessors 460, 470, 494, 490, 482, and 480, and the memory 492 of a UE450, and corresponding components of the Node B 410, as illustrated inFIG. 4. Those skilled in the art will comprehend that other suitablemeans for performing the functions to be described may be utilized aswell within the scope of the instant disclosure.

Here, the illustrated exemplary process starts with a UE (in an FDDsystem) utilizing as a serving cell a Node B in a wireless network. Inblock 902, the process monitors or measures various parameters of theserving cell, as well as various parameters of neighboring cells. Forexample, a UE may utilize a receiver 454 and a channel processor 494(see FIG. 4) to measure a pilot signal power of a common pilot channelCPICH corresponding to one or more cells in the general vicinity of theUE. When the UE detects 904 that one of the neighboring cells, calledcell n for convenience, begins to have certain signal qualities that areapproaching corresponding qualities of the signal provided from theserving cell, then in block 906 the UE may provide a Measurement Reportmessage on the uplink including an indication that the signal from therespective cell is within a reporting range (i.e., event 1a).

In the event that the system utilizes a legacy SCC, then following thesending 906 of the Measurement Report message from the UE, the systemresponds to the event 1a indication by providing 908 an Active SetUpdate message from an RNC to the UE, indicating that the UE should addthe corresponding cell to its Active Set. However, in the event that thesystem utilizes E-SCC, then following the sending 906 of the MeasurementReport message from the UE, the system responds to the event 1aindication by providing 910 an Active Set Update message from the RNC tothe UE, indicating that the UE should add the corresponding cell to itsActive Set, as well as pre-configuration information to enable the UE toutilize the corresponding cell upon the event that that cell becomes theserving cell in the future. Further, in block 912, the process providesinformation to enable the UE to change its Active Set and/or add orremove one of the Active Sets. For example, the RNC may notify the UEthat the second frequency is not configured in the target cell, suchthat the UE is aware that the corresponding cell is not DC-HSUPA-capableor that the RNC does not want to configure DC-HSUPA in the correspondingcell. In this instance the UE may only utilize one Active Set. Further,the RNC may notify the UE that the target cell uses one or moreadditional frequencies, such that the UE may add the correspondingActive Set or Sets. Thus, in general, according to various aspects ofthe disclosure, any number of radio links may be used by the TargetCell, and the UE may add or remove the corresponding number of ActiveSets, including removing all of the Active Sets from the UE. Stillfurther, when one or more Active Sets are added, or when one or more,but not all Active Sets are removed at the UE, one or more remainingActive Sets may be changed. That is, in an aspect of the disclosure,concomitant to the adding or removing of one or more Active Sets, cellslisted in a remaining Active Set may be added and/or removed, and theposition of a cell within the Active Set, such as the serving cell, maybe changed as well.

Following the messaging from the network, in block 914 the processmonitors or measures various parameters of the serving cell andneighboring cells at the UE. In block 916, the process determines that acertain signal quality of the target cell, such as a signal power of apilot signal CPICH from the corresponding target cell n, is greater thanthe corresponding signal quality of the serving cell. In this case, inblock 918, the process provides a message from the UE to the RNCincluding a Measurement Report message having an indicator of event 1d.

In the event that the system utilizes a legacy SCC, then following thesending of the Measurement Report message 918 from the UE, the systemresponds to the event 1d indication by providing a Transport ChannelReconfiguration Request 920 or other similar RRC message, such as aRadio Bearer Reconfiguration message or Physical Channel Reconfigurationmessage, including configuration information to enable the UE to utilizethe corresponding cell after the target cell becomes the serving cell.Further, in block 922, the process provides information to enable the UEto change its Active Set or remove one of the Active Sets. For example,the RNC may notify the UE that the second frequency is not configured inthe corresponding cell, such that the UE is aware that the correspondingcell is not DC-HSUPA-capable and only utilizes one Active Set. However,in the event that the system utilizes E-SCC, then following the sending918 of the Measurement Report message from the UE, the system respondsto the event 1d indication by providing 924 a physical layer indicatorover the air from the target cell to indicate for the UE to change tothe target cell. Here, the UE received pre-configuration information inblock 910 as a part of the E-SCC signaling, and further receivedinformation to enable the UE to change its Active Set or remove one ofthe Active Sets in block 912. Thus, providing the physical layerindicator 924 is sufficient to trigger a serving cell change. Thus, inblock 926, the process changes the UE to utilize the target cell as itsnew serving cell.

Several aspects of a telecommunications system have been presented withreference to an FDD W-CDMA system. As those skilled in the art willreadily appreciate, various aspects described throughout this disclosuremay be extended to other telecommunication systems, networkarchitectures and communication standards. By way of example, variousaspects may be extended to other UMTS systems such as TD-SCDMA, HighSpeed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access(HSUPA), High Speed Packet Access Plus (HSPA+) and TD-CDMA. Variousaspects may also be extended to systems employing Long Term Evolution(LTE) (in FDD, TDD, or both modes), LTE-Advanced (LTE-A) (in FDD, TDD,or both modes), CDMA2000, Evolution-Data Optimized (EV-DO), Ultra MobileBroadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20,Ultra-Wideband (UWB), Bluetooth, and/or other suitable systems. Theactual telecommunication standard, network architecture, and/orcommunication standard employed will depend on the specific applicationand the overall design constraints imposed on the system.

Several processors have been described in connection with variousapparatuses and methods. These processors may be implemented usingcomputer software, various electrical components such as electronichardware, or any combination thereof. Whether such processors areimplemented as hardware or software will depend upon the particularapplication and overall design constraints imposed on the system. By wayof example, a processor, any portion of a processor, or any combinationof processors presented in this disclosure may be implemented with amicroprocessor, microcontroller, digital signal processor (DSP), afield-programmable gate array (FPGA), a programmable logic device (PLD),a state machine, gated logic, discrete hardware circuits, and othersuitable processing components configured to perform the variousfunctions described throughout this disclosure. The functionality of aprocessor, any portion of a processor, or any combination of processorspresented in this disclosure may be implemented with software beingexecuted by a microprocessor, microcontroller, DSP, or other suitableplatform.

In one or more aspects of the disclosure, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media may be transitory ornon-transitory, and may include both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. Storage media may be anyavailable media that can be accessed by a general purpose or specialpurpose computer. By way of example, and not limitation, suchnon-transitory computer-readable media can comprise RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store desired program code means in the form of instructions or datastructures and that can be accessed by a general-purpose orspecial-purpose computer, or a general-purpose or special-purposeprocessor. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are transitory entities included in thedefinition of medium. Disk and disc, as used herein, includes compactdisc (CD), laser disc, optical disc, digital versatile disc (DVD),floppy disk and blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above should also be included within the scope ofcomputer-readable media. Computer-readable media may be embodied in acomputer-program product. By way of example, but without limitation, acomputer-program product may include a computer-readable medium inpackaging materials. Those skilled in the art will recognize how best toimplement the described functionality presented throughout thisdisclosure depending on the particular application and the overalldesign constraints imposed on the overall system.

It is to be understood that the specific order or hierarchy of steps inthe methods disclosed is an illustration of exemplary processes. Basedupon design preferences, it is understood that the specific order orhierarchy of steps in the methods may be rearranged. The accompanyingmethod claims present elements of the various steps in a sample order,and are not meant to be limited to the specific order or hierarchypresented unless specifically recited therein.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language of the claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. A phrase referring to“at least one of” a list of items refers to any combination of thoseitems, including single members. As an example, “at least one of: a, b,or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, band c. All structural and functional equivalents to the elements of thevarious aspects described throughout this disclosure that are known orlater come to be known to those of ordinary skill in the art areexpressly incorporated herein by reference and are intended to beencompassed by the claims. Moreover, nothing disclosed herein isintended to be dedicated to the public regardless of whether suchdisclosure is explicitly recited in the claims. No claim element is tobe construed under the provisions of 35 U.S.C. §112, sixth paragraph,unless the element is expressly recited using the phrase “means for” or,in the case of a method claim, the element is recited using the phrase“step for.”

What is claimed is:
 1. A method of communication in a wireless network,comprising: establishing communication with a user equipment (UE)utilizing a first carrier and a second carrier for each of an uplink anda downlink, wherein the UE maintains a first active set and a secondactive set, the first active set comprising a list of any cells in thewireless network that meet first criteria, the second active setcomprising a list of any cells in the wireless network that meet secondcriteria, the first active set corresponding to the first carrier, andthe second active set corresponding to the second carrier; receiving areport that a target cell meets third criteria; and transmitting, inresponse to receiving a report that the target cell meets the thirdcriteria, (i) configuration information for configuring wirelesscommunication with the target cell, wherein the configurationinformation indicates that the target cell is not a Release-9 capablecell, and (ii) a notification indicating that the target cell does notsupport the second carrier, the notification comprising informationenabling removal of the second active set.
 2. The method of claim 1,wherein the transmitting of the notification occurs prior to changing tothe target cell.
 3. The method of claim 1, wherein the first criteriacomprises a first threshold power level corresponding to a referencesignal transmitted from respective ones of the cells utilizing the firstcarrier, and wherein the second criteria comprises a second thresholdpower level corresponding to a reference signal transmitted fromrespective ones of the cells utilizing the second carrier.
 4. The methodof claim 3, wherein the third criteria comprises a certain power levelcompared to a measured power of a reference signal transmitted from apresent serving cell.
 5. The method of claim 1, wherein the notificationcomprises information indicating that the target cell supports an uplinklimited to one carrier frequency during a communication session.
 6. Themethod of claim 1, wherein the first carrier is an anchor carrier andthe second carrier is a secondary carrier.
 7. The method of claim 1,wherein the first carrier is a secondary carrier and the second carrieris an anchor carrier.
 8. The method of claim 1, further comprising:transmitting a downlink physical channel from each of the cells in thewireless network that meet the first criteria; and transmitting adownlink physical channel from each of the cells in the wireless networkthat meet the second criteria.
 9. The method of claim 1, wherein thenotification comprises a physical layer message.
 10. The method of claim1, wherein the notification utilizes a layer higher than a physicallayer.
 11. The method of claim 1, wherein the first active set ischanged to include a second list of cells in the wireless network thatmeet the first criteria, the second list of cells being different thanthe list of any cells in the wireless network that meet the firstcriteria.
 12. The method of claim 1, wherein the configurationinformation comprises an indicator to add the target cell to the firstactive set.
 13. The method of claim 1, further comprising: receiving areport that the target cell meets fourth criteria; and transmitting, inresponse to receiving the report of the target cell meets the fourthcriteria, an indicator to change to the target cell, wherein theindicator is configured to cause a change to the target cell such thatthe target cell becomes a new serving cell.
 14. An apparatus ofcommunication in a wireless network, comprising: means for establishingcommunication with a user equipment (UE) utilizing a first carrier and asecond carrier for each of an uplink and a downlink, wherein the UEmaintains a first active set and a second active set, the first activeset comprising a list of any cells in the wireless network that meetfirst criteria, the second active set comprising a list of any cells inthe wireless network that meet second criteria, the first active setcorresponding to the first carrier, and the second active setcorresponding to the second carrier; means for receiving a report that atarget cell meets third criteria; and means for transmitting, inresponse to receiving a report that the target cell meets the thirdcriteria, (i) configuration information for configuring wirelesscommunication with the target cell, wherein the configurationinformation indicates that the target cell is not a Release-9 capablecell, and (ii) a notification indicating that the target cell does notsupport the second carrier the notification comprising informationenabling removal of the second active set.
 15. The apparatus of claim14, wherein the means for transmitting of the notification occurs priorto changing to the target cell.
 16. The apparatus of claim 14, whereinthe first criteria comprises a first threshold power level correspondingto a reference signal transmitted from respective ones of the cellsutilizing the first carrier, and wherein the second criteria comprises asecond threshold power level corresponding to a reference signaltransmitted from respective ones of the cells utilizing the secondcarrier.
 17. The apparatus of claim 16, wherein the third criteriacomprises a certain power level compared to a measured power of areference signal transmitted from a present serving cell.
 18. Theapparatus of claim 14, wherein the notification comprises informationindicating that the target cell supports an uplink limited to onecarrier frequency during a communication session.
 19. The apparatus ofclaim 14, wherein the first carrier is an anchor carrier and the secondcarrier is a secondary carrier.
 20. The apparatus of claim 14, whereinthe first carrier is a secondary carrier and the second carrier is ananchor carrier.
 21. The apparatus of claim 14, further comprising: meansfor transmitting a downlink physical channel from each of the cells inthe wireless network that meet the first criteria; and means fortransmitting a downlink physical channel from each of the cells in thewireless network that meet the second criteria.
 22. The apparatus ofclaim 14, wherein the notification comprises a physical layer message.23. The apparatus of claim 14, wherein the notification utilizes a layerhigher than a physical layer.
 24. The apparatus of claim 14, wherein thefirst active set is changed to include a second list of cells in thewireless network that meet the first criteria, the second list of cellsbeing different than the list of any cells in the wireless network thatmeet the first criteria.
 25. The apparatus of claim 14, wherein theconfiguration information comprises an indicator to add the target cellto the first active set.
 26. The apparatus of claim 14, furthercomprising: means for receiving a report that the target cell meetsfourth criteria; and means for transmitting, in response to receivingthe report of the target cell meets the fourth criteria, an indicator tochange to the target cell, wherein the indicator is configured to causea change to the target cell such that the target cell becomes a newserving cell.
 27. A computer program product for use in a wirelessnetwork, comprising: a non-transitory computer-readable mediumcomprising code for: establishing communication with a user equipment(UE) utilizing a first carrier and a second carrier for each of anuplink and a downlink, wherein the UE maintains a first active set and asecond active set, the first active set comprising a list of any cellsin the wireless network that meet first criteria, the second active setcomprising a list of any cells in the wireless network that meet secondcriteria, the first active set corresponding to the first carrier, andthe second active set corresponding to the second carrier; receiving areport that a target cell meets third criteria; and transmitting, inresponse to receiving a report that the target cell meets the thirdcriteria, (i) configuration information for configuring wirelesscommunication with the target cell, wherein the configurationinformation indicates that the target cell is not a Release-9 capablecell, and (ii) a notification indicating that the target cell does notsupport the second carrier the notification comprising informationenabling removal of the second active set.
 28. The computer programproduct of claim 27, wherein the code for transmitting of thenotification occurs prior to changing to the target cell.
 29. Thecomputer program product of claim 27, wherein the first criteriacomprises a first threshold power level corresponding to a referencesignal transmitted from respective ones of the cells utilizing the firstcarrier, and wherein the second criteria comprises a second thresholdpower level corresponding to a reference signal transmitted fromrespective ones of the cells utilizing the second carrier.
 30. Thecomputer program product of claim 29, wherein the third criteriacomprises a certain power level compared to a measured power of areference signal transmitted from a present serving cell.
 31. Thecomputer program product of claim 27, wherein the notification comprisesinformation indicating that the target cell supports an uplink limitedto one carrier frequency during a communication session.
 32. Thecomputer program product of claim 27, wherein the first carrier is ananchor carrier and the second carrier is a secondary carrier.
 33. Thecomputer program product of claim 27, wherein the first carrier is asecondary carrier and the second carrier is an anchor carrier.
 34. Thecomputer program product of claim 27, further comprising: code fortransmitting a downlink physical channel from each of the cells in thewireless network that meet the first criteria; and code for transmittinga downlink physical channel from each of the cells in the wirelessnetwork that meet the second criteria.
 35. The computer program productof claim 27, wherein the notification comprises a physical layermessage.
 36. The computer program product of claim 27, wherein thenotification utilizes a layer higher than a physical layer.
 37. Thecomputer program product of claim 27, wherein the first active set ischanged to include a second list of cells in the wireless network thatmeet the first criteria, the second list of cells being different thanthe list of any cells in the wireless network that meet the firstcriteria.
 38. The computer program product of claim 27, wherein theconfiguration information comprises an indicator to add the target cellto the first active set.
 39. The computer program product of claim 27,further comprising: code for receiving a report that the target cellmeets fourth criteria; and code for transmitting, in response toreceiving the report of the target cell meets the fourth criteria, anindicator to change to the target cell, wherein the indicator isconfigured to cause a change to the target cell such that the targetcell becomes a new serving cell.
 40. An apparatus for communication in awireless network, comprising: at least one processor; and a memorycoupled to the at least one processor, wherein the at least oneprocessor is configured to: establish communication with a userequipment (UE) utilizing a first carrier and a second carrier for eachof an uplink and a downlink, wherein the UE maintains a first active setand a second active set, the first active set comprising a list of anycells in the wireless network that meet first criteria, the secondactive set comprising a list of any cells in the wireless network thatmeet second criteria, the first active set corresponding to the firstcarrier, and the second active set corresponding to the second carrier;receive a report that a target cell meets third criteria; and transmit,in response to receiving a report that the target cell meets the thirdcriteria, (i) configuration information for configuring wirelesscommunication with the target cell, wherein the configurationinformation indicates that the target cell is not a Release-9 capablecell, and (ii) a notification indicating that the target cell does notsupport the second carrier the notification comprising informationenabling removal of the second active set.
 41. The apparatus of claim40, wherein the transmitting of the notification occurs prior tochanging to the target cell.
 42. The apparatus of claim 40, wherein thefirst criteria comprises a first threshold power level corresponding toa reference signal transmitted from respective ones of the cellsutilizing the first carrier, and wherein the second criteria comprises asecond threshold power level corresponding to a reference signaltransmitted from respective ones of the cells utilizing the secondcarrier.
 43. The apparatus of claim 42, wherein the third criteriacomprises a certain power level compared to a measured power of areference signal transmitted from a present serving cell.
 44. Theapparatus of claim 40, wherein the notification comprises informationindicating that the target cell supports an uplink limited to onecarrier frequency during a communication session.
 45. The apparatus ofclaim 40, wherein the first carrier is an anchor carrier and the secondcarrier is a secondary carrier.
 46. The apparatus of claim 40, whereinthe first carrier is a secondary carrier and the second carrier is ananchor carrier.
 47. The apparatus of claim 40, wherein the at least oneprocessor is further configured to: transmit a downlink physical channelfrom each of the cells in the wireless network that meet the firstcriteria; and transmit a downlink physical channel from each of thecells in the wireless network that meet the second criteria.
 48. Theapparatus of claim 40, wherein the notification comprises a physicallayer message.
 49. The apparatus of claim 40, wherein the notificationutilizes a layer higher than a physical layer.
 50. The apparatus ofclaim 40, wherein the first active set is changed to include a secondlist of cells in the wireless network that meet the first criteria, thesecond list of cells being different than the list of any cells in thewireless network that meet the first criteria.
 51. The apparatus ofclaim 40, wherein the configuration information comprises an indicatorto add the target cell to the first active set.
 52. The apparatus ofclaim 40, wherein the at least one processor is further configured to:receive a report that the target cell meets fourth criteria; andtransmit, in response to receiving the report of the target cell meetsthe fourth criteria, an indicator to change to the target cell, whereinthe indicator is configured to cause a change to the target cell suchthat the target cell becomes a new serving cell.